Cardiopulmonary Resuscitation (CPR) Device With Blood Flow Cardiopulmonary Resuscitation Value Feedback And Interface

ABSTRACT

A cardiopulmonary resuscitation device with blood flow cardiopulmonary resuscitation value feedback is disclosed. The device has a blood flow sensor where a computer converts a blood flow value to a cardiopulmonary resuscitation value and provides the cardiopulmonary resuscitation value to a sensory indicator, a mechanical chest compression device or another computer, computer network, or computing device. The cardiopulmonary resuscitation value provides information on improving chest compressions during a medical emergency involving cardiopulmonary resuscitation by an emergency medical worker. The cardiopulmonary resuscitation may, in some embodiments, be aided by a mechanical chest compression device. The device improves patient outcome from cardiopulmonary resuscitation.

CROSS REFERENCE TO RELATED PATENT APPLICATIONS

This application claims priority to U.S. Patent Application Ser. No.63/126,716 filed on Dec. 17, 2020 entitled “Medical Device”, and U.S.Patent Application Ser. No. 63/173,887 filed on Apr. 12, 2021 entitled“Self-Adjusting Mechanical Chest Compression Device”, the entiredisclosures of which are incorporated herein by reference in theirentirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENTBACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates generally to medical devices, and moreparticularly to a cardiopulmonary resuscitation (CPR) device that usesblood flow cardiopulmonary resuscitation value feedback for improvingthe outcome of cardiopulmonary resuscitation.

2. Description of the Related Art

Cardiopulmonary Resuscitation (CPR) is a very established medicalprocedure for reviving a patient who has suffered a medical emergencythat has rendered their heart unable to pump blood. In such a situation,chest compressions are performed by an emergency medical worker toestablish blood perfusion such that blood flows to vital organs and thebrain with subsequent restoration of heart rhythm. CardiopulmonaryResuscitation (CPR) is thus a life saving technique that must beperformed immediately and with proper technique in order to save thelife of the patient. Proper technique includes timing of the chestcompression, force applied to the chest during the chest compression,location of the chest compression, as well as the amount of compressivetravel during each chest compression. Unfortunately there is currentlyno way for the emergency medical worker to obtain feedback on theeffectiveness of each chest compression, thus leaving a very undesirableelement of chance to such a critical medical procedure. To make mattersthat much more difficult, the physiological makeup of each patient isdifferent, and thus necessitates slightly different chest compressiontechniques for each patient. For example, overweight and underweightpatients present very different requirements for compressive force andplacement of each chest compression.

What is needed is a way to provide real time feedback on theeffectiveness of chest compression being provided by an emergencymedical worker such that the emergency medical worker can modify theirchest compression technique so that it provides optimal blood perfusion.

What is also needed is a way to provide real time feedback on theeffectiveness of chest compression being performed by a mechanical chestcompression device to that mechanical chest compression device such thatchest compressions being performed by the mechanical chest compressiondevice are optimal for blood perfusion.

What is also needed is a way to provide real time information on theeffectiveness of chest compressions during cardiopulmonary resuscitationto emergency medical workers and also to provide information from othersources to emergency medical workers or a mechanical chest compressiondevice so that the chest compressions are optimal for blood perfusion.

The present invention and the various embodiments described andenvisioned herein provide for such unmet needs.

BRIEF SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided acardiopulmonary resuscitation (CPR) device that improves the outcome ofcardiopulmonary resuscitation (CPR). The device uses a non-invasiveblood flow sensor to determine cardiopulmonary function during CPR andin turn provides real-time feedback to the individual performing CPR ona patient. Cardiopulmonary functions may include heart rate, bloodvelocity, blood volume, blood pressure, and blood oxygenation. Real-timefeedback is provided to the individual performing CPR by way of anaudible or visual signal. A change in the characteristics of the signal(for example, with an audible signal, change in volume or frequency ofthe audible signal) indicates how effective or ineffective each chestcompression is, and alerts the CPR provider to either continue withtheir course of action or change it (change placement of the chestcompression, timing, depth or force of the chest compression).

In some embodiments, the blood flow sensor provides a signal to amechanical chest compression device which in turn adjusts the chestcompression or placement of the chest compressor on the patient. Themechanical chest compression device may have an X-Y rail arrangement formoving the location of the chest compressor in response to informationfrom the blood flow sensor.

In some embodiments, the cardiopulmonary resuscitation (CPR) device is awearable device that contains a non-invasive blood flow sensor and iscapable of providing event data to an event recorder and also an alertthrough a network.

The foregoing has been provided by way of introduction, and is notintended to limit the scope of the invention as described by thisspecification, claims, and the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described by reference to the following drawings,in which like numerals refer to like elements, and in which:

FIG. 1 depicts a block diagram of the main constituent components of auser based embodiment of the cardiopulmonary resuscitation device withblood flow cardiopulmonary resuscitation value feedback of the presentinvention;

FIG. 2 depicts a block diagram of the main constituent components of awearable device embodiment of the cardiopulmonary resuscitation devicewith blood flow cardiopulmonary resuscitation value feedback of thepresent invention;

FIG. 3 depicts a block diagram of the main constituent components of achest compression device embodiment of the cardiopulmonary resuscitationdevice with blood flow cardiopulmonary resuscitation value feedback ofthe present invention;

FIG. 4 is a data flow diagram depicting the creation of patient specificparameters;

FIG. 5 is a data flow diagram depicting a user based method for improvedpatient outcome;

FIG. 6 is a data flow diagram depicting a mechanical chest compressionbased method for improved patient outcome;

FIG. 7 is a data flow diagram depicting a further mechanical chestcompression based method for improved patient outcome;

FIG. 8 is a data flow diagram depicting a feedback mechanical chestcompression based method for improved patient outcome;

FIG. 9 is a perspective view of a mechanical chest compression device ofthe present invention;

FIG. 10 is a front view of the mechanical chest compression device ofthe present invention;

FIG. 11 is a back view of the mechanical chest compression device of thepresent invention;

FIG. 12 is a right side view of the mechanical chest compression deviceof the present invention;

FIG. 13 is a left side view of the mechanical chest compression deviceof the present invention;

FIG. 14 is a top view of the mechanical chest compression device of thepresent invention; and

FIG. 15 is a bottom view of the mechanical chest compression device ofthe present invention.

The present invention will be described in connection with a preferredembodiment, however, it will be understood that there is no intent tolimit the invention to the embodiment described. On the contrary, theintent is to cover all alternatives, modifications, and equivalents asmay be included within the spirit and scope of the invention as definedby this specification, claims, and drawings attached hereto.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As will be further described herein, a cardiopulmonary resuscitationdevice with blood flow cardiopulmonary resuscitation value feedback isdisclosed.

The cardiopulmonary resuscitation device monitors blood flownon-invasively, and provides real time feedback during and/or after anemergency medical procedure. The real time feedback includes acardiopulmonary resuscitation value that is derived from a measuredblood flow value and in turn provides feedback to emergency medicalpersonnel regarding the adequacy of their cardiopulmonary resuscitationactions. The feedback may come in a variety of forms, including audible,visual, tactile, or in some embodiments as an electronic feedback signalto a mechanical chest compression device instructing the mechanicalchest compression device to take certain actions or modify certainactions. The cardiopulmonary resuscitation value is derived from ameasured blood flow value as well as other patient specific parametersto provide real time feedback to emergency medical personnel resultingin optimal chest compressions. This optimization would not be possiblewith blood flow monitoring alone, and will be described in furtherdetail below by reference to the drawings.

Turning first to FIG. 1, a block diagram of the main constituentcomponents of a user based embodiment 100 of the cardiopulmonaryresuscitation device with blood flow cardiopulmonary resuscitation valuefeedback is depicted. In this embodiment, a sensory indicator providesfeedback directly to an emergency medical care provider to allow theemergency medical care provider to adjust their chest compressions basedon the sensory indicator.

A blood flow sensor 107 is applied to a patient non-invasively through acuff, a strap, a band or a similar arrangement that provides skincontact over a blood vessel. There may be a plurality of blood flowsensors configured as a strap, cuff or similar wearable arrangement. Theblood flow sensors may employ photo acoustics, doppler, ultrasound,duplex doppler ultrasonography, electromagnetics, optics, laser doppler,fiber optics or the like. In addition, the blood flow sensor 107 mayinclude pulse oximetry for determining blood oxygen saturation. In onepreferred embodiment, photoacoustic doppler is used for the blood flowsensor 107.

Placement of the blood flow sensor 107 would, in one embodiment,preferably be on the brachial artery. The blood flow sensor 107 mayinclude a clear or partially clear cuff, strap or band such that thesensors are visible to an emergency medical provider during placement,ensuring correct placement of the blood flow sensor 107 during anextremely time sensitive procedure. The blood flow sensor 107 providesrate of flow and flow velocity in real time for subsequent downstreamprocessing. Flow velocity can also be used to determine blood pressurewhich is in turn provided to the computer system 101 for subsequentdetermination of cardiopulmonary resuscitation values. While the bloodflow sensor 107 may provide an analog signal representative of bloodflow velocity or volume, an analog to digital converter 105 may beemployed to convert the analog signal to digital signals that are sentto the computer system 101 through an interface 103. The interface 103may simply be a communications interface such as RS-232, RS-422, RS-485,other serial or parallel interfaces, or may employ a wireless orencrypted standard.

A computer system 101 can be seen that has a processor, memory, andaccess to computer readable media. The computer system 101 receivesblood flow data from the interface 103 for subsequent conversion to acardiopulmonary resuscitation value. Within the computer system 101, acomputer/processor 111 executes a computer program 113 that executes thesteps of retrieving a binary representation of the blood flow sensoroutput; converting the binary representation of the blood flow sensoroutput to a blood flow value; assigning the blood flow value to acardiopulmonary resuscitation value; converting the cardiopulmonaryresuscitation value to a user feedback value; and providing the userfeedback value to a sensory indicator 119. In some embodiments of thepresent invention, the blood flow value is converted to a cardiac outputvalue. The cardiac output value is calculated by the computer program113 using blood flow values with sensed heart rate and estimated strokevolume. In one embodiment of the present invention, the cardiac outputvalue is determined with Fick's Formula. The sensory indicator 119 maybe an audible indicator such as a tone or a signal that changes inamplitude, frequency, or duration/cadence as the emergency medicalresponder performs chest compressions that are more conforming or lessconforming to an optimal value as defined by cardiopulmonaryresuscitation values that are provided in real time or near real time tothe emergency medical responder. The sensory indicator may also providea visual indicator for user feedback. In some embodiments the visualindicator is a light or a computer display. The computer system 101 mayalso send or receive remote diagnostics 117 such as, for example,medication status, medical records, archival or historicalcardiovascular data, and the like.

The system may also, in some embodiments, determine blood pressure,heart rate, temperature, respiratory rate, end tidal CO₂, pH/blood gas,heart rhythm, oxygen saturation, blood glucose, and the like. In someembodiments, the system of the present invention can take an action whena value of a sensed function is exceeded or goes below a certain value.

In some embodiments the system integrates with electronic medicalrecords, providing ease of charting and order entry. This would allowanyone involved in the patient's care to have real time updates on thepatient's vitals. It would also allow ease of determining the timing ofinterventions such as medications, CPR, oxygen administration,defibrillation, and the like. The system may also, in some embodiments,provide medical alerts to providers when critical changes in vitalsoccur so that treatment is provided promptly when needed.

In its simplest form, the cardiopulmonary resuscitation is directly andlinearly correlated to a blood flow value. For example, decreased bloodflow results in a lower (or in some embodiments a higher)cardiopulmonary resuscitation value, which in turn relates to a lower(or in some embodiments a higher) user feedback value. Since the userfeedback value is provided to a sensory indicator 119, a lower bloodflow may result in a lower sensory indication (for example, a lowervolume audio signal) and alternatively, a higher blood flow would resultin a higher sensory indication (for example, a higher volume audiosignal). The sensory indicator may also provide feedback in the form ofslower or faster cadence, higher or lower pitch (sound frequency), andthe like. The cardiopulmonary resuscitation value may also contain avalue that corresponds to placement of the hand during compression,depth of the compression, force of the compression, and the like, andmay provide user feedback for these variables as another sensoryindicator (for example, light or haptics), or as a multi-dimensionalaudio or visual signal (where, for example, in an audio signal amplitude(volume) represents blood flow, frequency represents force of the chestcompression, and cadence represents hand placement during eachcompression).

In some embodiments, the cardiopulmonary resuscitation value is adjustedor modified based on patient specific parameters. Patient specificparameters include, but are not limited to, patient age, patient weight,patient height, patient age, patient medication history, patient medicalhistory, and patient cardiovascular history. With an adjusted ormodified cardiopulmonary resuscitation value, the user feedback value isalso modified or adjusted accordingly. While the American HeartAssociation recommends chest compressions at a rate of 100-120 perminute and to a depth of at least two inches, and not greater than 2.4inches, these figures may vary based on the patient. Also, and veryimportantly, with current CPR procedures, there is no way for theprovider of CPR to know if they are performing chest compressionsproperly at all.

While a sensory indicator embodiment is valuable in a majority of CPRcases, a wearable device that provides blood flow feedback may provideadditional or enhanced life saving utility. FIG. 2 depicts a blockdiagram of the main constituent components of a wearable deviceembodiment of the cardiopulmonary resuscitation device with blood flowvalue feedback. A wearable device 201 may include a watch, a cheststrap, an ankle strap, a clothing item, or the like. The blood flowsensor 203 may employ a plurality of blood flow sensors of the same ordifferent technologies. The blood flow sensors may use photo acoustics,doppler, ultrasound, electromagnetics, optics, or the like. In addition,the blood flow sensor 203 may include pulse oximetry for determiningblood oxygen saturation. In one preferred embodiment, photoacousticdoppler is used for the blood flow sensor 203. In addition to a bloodflow sensor 203, the wearable device 201 includes a processor 205 thatexecutes a computer program 207 that contains the steps of retrieving abinary representation of the blood flow sensor output; converting thebinary representation of the blood flow sensor output to a blood flowvalue; assigning the blood flow value to a cardiopulmonary resuscitationvalue; converting the cardiopulmonary resuscitation value to a userfeedback value; and providing the user feedback value to a sensoryindicator 209. The sensory indicator 209 may be an audible indicatorsuch as a tone or a signal that changes in amplitude, frequency, orduration/cadence as the emergency medical responder performs chestcompressions that are more conforming or less conforming to an optimalvalue as defined by cardiopulmonary resuscitation values that areprovided in real time or near real time to the emergency medicalresponder. While one program 207 of the wearable device 201 monitorsblood flow in the event of cardiopulmonary resuscitation, as previouslydescribed, a patient may also monitor blood flow with the wearabledevice 201 for the purpose on ongoing medical monitoring. In such asituation, an event recorder 211 may be contained in the wearable device201, or in a networked computer or device, and is configured to sendblood flow data through a network 215 to a node C1 (217) or a pluralityof nodes C2 (219), C3 (221), . . . Cn (223). An optional database 213may be included that captures event data from a patient for medicaldiagnostic and treatment purposes. Data sent from the wearable device toa network may be sent to, for example, a monitoring device or system toprovide data to medical providers and potentially to a 911 center or thelike. Data may also be sent that includes medical charts and historicalmedical data either to a network or to the device of the presentinvention or a peripheral thereof.

Turning now to FIG. 3 where a block diagram of the main constituentcomponents of a chest compression device embodiment of thecardiopulmonary resuscitation device with blood flow cardiopulmonaryresuscitation value feedback is depicted. The cardiopulmonaryresuscitation device with blood flow cardiopulmonary resuscitation valuefeedback is provided with a chest compression device interface (CCDInterface 301) where the cardiopulmonary resuscitation value isconverted to a chest compression value and the chest compression valueis provided to a mechanical chest compression device 303. Instead ofproviding a sensory indicator to a user alone, the CCD interfaceprovides information that adjusts chest compression rate, depth, force,and placement to the mechanical chest compression device 303.

Historical or archival data from past blood flow data collections may beused to improve patient outcomes by helping to define patient specificparameters. FIG. 4 is a data flow diagram depicting the creation ofpatient specific parameters. As previously discussed, a database ofarchival data 115 comprises historical data 401 from previous patientcardiopulmonary events, parametric data 403 that defines patientspecific parameters such as weight, age, and the like, calculated data405 where data such as cardiac output is defined and determined, andinput data 407 where information such as medication history orcardiovascular data is entered. This archival data 115 may be from manypatients over many time intervals. A parsing engine 409 acts on thisarchival data to determine patient specific parameters which are thendownloaded to a patient device and provided to a sensory indicatorand/or a chest compression device.

While the blood flow sensor is essential for beginning the process ofproviding user feedback to a provider of cardiopulmonary resuscitationduring a medical emergency, it is essential that blood flow values fromthe blood flow sensor are ultimately converted to meaningful signaling,whether that signaling is a sensory indicator or instructions providedto a mechanical chest compression device. This conversion process issoftware based, and performed with a processor/computer. Hemodynamics isa complex topic, and the use of software to not only convert blood flowvalues to useful outputs but also to modify those useful output valuesbased on patient centric values provides for an optimal instruction setfor improved patient outcome. While in its simplest form, sensing bloodflow or lack of blood flow and alerting the emergency medical providerto this binary condition is a fundamental and basic component of thepresent invention, optimizing blood flow during cardiopulmonaryresuscitation not only improves patient outcome but also reducescomplications associated with lack of blood flow. Blood flow velocitycan be expressed as:

V=Q/A

Where V is blood flow velocity (cm/s), Q is blood flow (ml/s) and A iscross sectional area (cm²). Blood flow can vary based on the smoothnessof the vessels and other factors, thus making optimal blood flow patientspecific. A preferred placement of the blood flow sensor of the presentinvention is the brachial artery. A blood flow value (BFV) may beexpressed in ml/s or ml/min. For example, brachial artery blood flow maybe 600-800 ml./min. This value is then converted to a cardiopulmonaryresuscitation (CPR) value, which may be, in some embodiments, the sameas the initial blood flow value (for example, a blood flow value of 800ml/min may be assigned a CPR value of 800. This CPR value may then beacted on or modified by a variety of parameters such as patientparameters to ensure that a feedback value that indicates optimal bloodflow for a given chest compression is the same regardless of the patientand differences in their hemodynamic characteristics. For example, a CPRvalue of 800 may indicate that optimal blood flow is occurring inpatient A, whereas optimal blood flow for patient b in the brachialartery may be 700 ml/min. Thus, a CPR value for patient A may be 800 whohas an optimal blood flow value of 800 ml/min. and the CPR value forpatient B may also be 800 where patient B has an optimal blood flowvalue of 700 ml/min. For simplicity of this example, if a CPR value of800 indicates optimal blood flow, the User Feedback Value would begreatest (for example, greatest amplitude of a tone being indicative ofoptimal blood flow) at a CPR value of 800. Thus, if the amplitude(volume) of a sensory indicator is greatest at a CPR value of 800, andthe maximum volume of the sensory indicator is a 10 (of course thesedecimal numbers are arbitrary and would most likely be represented inbinary as part of the computer program of the present invention), then aCPR value of 800 would be assigned a user feedback value of 10. Whilethese numbers are arbitrary, the data flow and data conversion of thisexample would apply to a variety of situations of the present invention.

With this example in mind, an example of data flow of the presentinvention is provided by way of FIG. 5, which depicts a data flowdiagram of a user based method for improved patient outcome 500. Thedata flow generally corresponds with the previously described detaileddescription provided herein. It should be noted that the steps in FIG. 5are collected by a database of archival data 115 to continually improvethe device of the present invention by generating patient parameters 411that may include, for example, modification of the user feedback valueor cardiopulmonary resuscitation value, administration of medications,and the like. In some embodiments, however, collection of data orarchiving of data is not present. In step 501, the output of the bloodflow sensor is received and converted to a blood flow value in step 503.This may, in some embodiments, involve the conversion from an analogsignal to a digital signal. The blood flow value that has beendetermined is then used to assign a CPR Value (CPRV) to the blood flowvalue in step 505. The CPR Value (CPRV) is then converted to a UserFeedback Value (UFV) in step 507. In step 509, the User Feedback Value(UFV) is provided to a sensory indicator such as an audible or a visualsignal or signals to provide feedback to a user (a provider ofcardiopulmonary resuscitation to a patient). It should be noted thatthese steps may be executed in plurality, and may be real time or nearreal time in order to provide the user with real time feedback of theeffectiveness of each chest compression as well as the effectiveness ofother actions that may be taken during cardiopulmonary resuscitation(such as, for example, mouth to mouth resuscitation, administration ofmedication, and the like). In addition, it should be noted that thecalculation and definition of these values has been previously describedherein by way of example, and not limitation.

In some embodiments, a mechanical chest compression device (automatedCPR machine) is included with the device for improving the outcome ofcardiopulmonary resuscitation. FIG. 6 is a data flow diagram depicting amechanical chest compression based method for improved patient outcome.In step 601, the blood flow value previously determined in step 503 isconverted to a Cardiac Output Value (COV). Blood flow can be used todetermine stroke volume (estimated based on blood flow measured in theartery where the blood flow sensor has been placed) and from there acardiac output value is determined by multiplying stroke volume by heartrate (compressively induced rate for example). A Cardiac Output Value(COV) is useful to medical practitioners during and aftercardiopulmonary resuscitation, and may, in some embodiments, be used toprovide user feedback to a sensory indicator or control of a mechanicalchest compression device. The Cardiac Output Values gathered during andafter cardiopulmonary resuscitation may also be archived in a databasefor improved patient treatment.

In step 603, the CPR Value (CPRV) is converted to a chest compressionvalue (CCV) and provided to a mechanical chest compression device instep 605. By providing CPR Values (CPRVs) to a mechanical chestcompression device customized chest compressions and ventilation periodscan be determined based on blood flow values and other inputs that mayhave been used to determine CPR Values. A digital interface ispreferably provided that converts the stream of CPR Values beingcalculated in real time or near real time to digital representations(digital numerical values and perhaps additional information tosupplement the CPR Values such as machine control information) that arein turn received by the mechanical chest compression device and used tomodify key physical parameters such as stroke depth, stroke rate,ventilation interval and timing, and the like. In the embodimentdescribed by way of FIG. 6, the parametric modifications made during useof the mechanical chest compression device are primarily directed atZ-axis functionality (chest compression stroke modality).

Turning now to FIG. 7, a data flow diagram depicting a furthermechanical chest compression based method for improved patient outcomecan be seen. In this embodiment, the mechanical chest compression deviceis equipped with mechanically adjustable and motorized racks, slides orscaffolding that allows the chest compression piston to be moved alongboth the X-axis and the Y-axis, thus adjusting the placement of thechest compression piston (plunger) on the chest of the patient. Thus, instep 701 the CPR Value (CPRV) is converted to both a Chest CompressionValue (CCV) and an X-Y Coordinate Value (XYV) and in step 703 the ChestCompression Value (CCV) and XY Coordinate Value (XYV) are provided tothe mechanical chest compression device. This is done in real time ornear real time, with the mechanical chest compression device makingadjustments in the X, Y and Z axis in real time or near real time duringa CPR procedure.

FIG. 8 depicts a data flow diagram of a feedback mechanical chestcompression based method for improved patient outcome where the ongoingchanges in X, Y and Z position of the mechanical chest compressiondevice piston (plunger) are received in step 801 and compared to theongoing stream of CPR values, resulting in the provision of modified X-Ycoordinate values (and in some embodiments Z coordinate values) to themechanical chest compression device.

Mechanical chest compression device functionality, which includes ablood flow sensor and related software and processor, may be integratedwith a mechanical chest compression device or may, in some embodiments,be a detachable peripheral that is connected to the electronic unit ofthe mechanical chest compression device by way of a cable or a wirelessinterface.

FIG. 9 is a perspective view of a mechanical chest compression device ofthe present invention 900. A housing and backplate 901 can be seen alongwith electronics controls 903. In some embodiments, the housing attachesdirectly to a bed or stretcher without the necessity of placing abackplate under the patient, thus saving valuable time. A blood flowsensor cuff 905 can be seen attached to a cable 907 that interfaces withthe electronics controls 903. A piston (plunger) 909 can also be seen.The piston (plunger) 909 is driven be a linear device such as a linearmechanical or electrical or electromechanical actuator. In someembodiments, the actuator is pneumatic or hydraulic.

FIG. 10 is a front view of the mechanical chest compression device ofthe present invention 900. Above the piston (plunger) 909, an X-Yadjustment arrangement can be seen, which allows the placement of thepiston (plunger) 909 to be modified based on control input derived fromCPR Values (CPRVs).

FIG. 11 is a back view of the mechanical chest compression device of thepresent invention showing clearly the blood flow sensor cuff 905.

FIG. 12 is a right side view of the mechanical chest compression deviceof the present invention.

FIG. 13 is a left side view of the mechanical chest compression deviceof the present invention.

FIG. 14 is a top view of the mechanical chest compression device of thepresent invention.

Lastly, FIG. 15 is a bottom view of the mechanical chest compressiondevice of the present invention.

Having described and illustrated the principles, components and methodsof the present invention by reference to one or more preferredembodiments, it should be apparent that the preferred embodiment(s)described and envisioned herein may be modified in arrangement anddetail without departing from the spirit and broad scope of the presentinvention, and that these modifications and variations are to beconsidered and construed as being included in the present applicationand invention described herein.

What is claimed is:
 1. A device for improving the outcome ofcardiopulmonary resuscitation, the device comprising: a blood flowsensor configured to make contact with the skin of a patient; a housingfor retaining the blood flow sensor; and analogy to digital converterconfigured to received the output of the blood flow sensor and convertthe output to a binary representation; a computer having a processor,memory, access to computer readable media; an interface configured toreceive the binary representation of the blood flow sensor output fromthe analog to digital converter; a computer program stored on thecomputer readable media where the computer program executes the stepsof: retrieving the binary representation of the blood flow sensoroutput; converting the binary representation of the blood flow sensoroutput to a blood flow value; assigning the blood flow value to acardiopulmonary resuscitation value; converting the cardiopulmonaryresuscitation value to a user feedback value; and providing the userfeedback value to a sensory indicator.
 2. The device for improving theoutcome of cardiopulmonary resuscitation as recited in claim 1, whereinthe blood flow sensor is a photoacoustic doppler sensor.
 3. The devicefor improving the outcome of cardiopulmonary resuscitation as recited inclaim 1, wherein the housing is a strap for placement around a body partof a patient.
 4. The device for improving the outcome of cardiopulmonaryresuscitation as recited in claim 3, wherein the strap has a visualaperture to allow a user to determine proper placement of the sensor. 5.The device for improving the outcome of cardiopulmonary resuscitation asrecited in claim 1, wherein the sensory indicator is a sound that variesin frequency based on the user feedback value at a given point intreatment time.
 6. The device for improving the outcome ofcardiopulmonary resuscitation as recited in claim 1, wherein the sensoryindicator is a sound that varies in amplitude based on the user feedbackvalue at a given point in treatment time.
 7. The device for improvingthe outcome of cardiopulmonary resuscitation as recited in claim 1,wherein the sensory indicator is a sound that varies in both frequencyand amplitude based on the user feedback value at a given point intreatment time.
 8. The device for improving the outcome ofcardiopulmonary resuscitation as recited in claim 1, wherein the sensoryindicator is a visual indicator.
 9. The device for improving the outcomeof cardiopulmonary resuscitation as recited in claim 8, wherein thevisual indicator is a computer display.
 10. The device for improving theoutcome of cardiopulmonary resuscitation as recited in claim 8, whereinthe visual indicator is a light source.
 11. A device for improving theoutcome of cardiopulmonary resuscitation, the device comprising: a bloodflow sensor configured to make contact with the skin of a patient; ahousing for retaining the blood flow sensor; a mechanical chestcompression device comprising a digital interface configured to receivea chest compression value; an analog to digital converter configured toreceive the output of the blood flow sensor and convert the output to abinary representation; a computer having a processor, memory, and accessto computer readable media; an interface configured to receive thebinary representation of the blood flow sensor output from the analog todigital converter; a computer program stored on the computer readablemedia where the computer program executes the steps of: retrieving thebinary representation of the blood flow sensor output; converting thebinary representation of the blood flow sensor output to a blood flowvalue; assigning the blood flow value to a cardiopulmonary resuscitationvalue; converting the cardiopulmonary resuscitation value to a chestcompression value; and providing the chest compression value to themechanical chest compression device.
 12. The device for improving theoutcome of cardiopulmonary resuscitation as recited in claim 11, whereinthe blood flow sensor is a photoacoustic doppler sensor.
 13. Amechanical chest compression device, the device comprising: a bodyhousing: a back plate; a chest compressor comprising a piston, an x-axisrail, a y-axis rail, and a compression head; a computer having aprocessor, memory, and access to computer readable media; an interfaceconfigured to provide the coordinates of the x-axis rail and the y-axisrail and receive instructions to change the coordinates of the x-axisrail and the y-axis rail; and a device for improving the outcome ofcardiopulmonary resuscitation, the device comprising: a blood flowsensor configured to make contact with the skin of a patient; a housingfor retaining the blood flow sensor; an analog to digital converterconfigured to receive the output of the blood flow sensor and convertthe output to a binary representation; a computer having a processor,memory, and access to computer readable media; an interface configuredto receive the binary representation of the blood flow sensor outputfrom the analog to digital converter; a computer program stored on thecomputer readable media where the computer program executes the stepsof: retrieving the binary representation of the blood flow sensoroutput; converting the binary representation of the blood flow sensoroutput to a blood flow value; assigning the blood flow value to acardiopulmonary resuscitation value; converting the cardiopulmonaryresuscitation value to a chest compression value; and providing thechest compression value to the mechanical chest compression device. 14.The mechanical chest compression device as recited in claim 13, whereinthe computer program stored on computer readable media further comprisesthe steps of: converting the cardiopulmonary resuscitation value to anX-Y coordinate value; providing the X-Y coordinate value to themechanical chest compress on device.
 15. The mechanical chestcompression device as recited in claim 13, wherein the computer programstored on computer readable media further comprises the steps of:receiving an X-Y coordinate value from the mechanical chest compressiondevice; comparing the X-Y coordinate value to a cardiopulmonaryresuscitation value; and providing a modified X-Y coordinate value tothe mechanical chest compression device.
 16. The mechanical chestcompression device as recited in claim 13, wherein the computer programstored on computer readable media further comprises the steps of:converting the cardiopulmonary resuscitation value to a user feedbackvalue; and providing the user feedback value to a sensory indicator. 17.The mechanical chest compression device as recited in claim 16, whereinthe sensory indicator is an audible indicator.
 18. The mechanical chestcompression device as recited in claim 16, wherein the sensory indicatoris a visual indicator.
 19. The mechanical chest compression device asrecited in claim 13, wherein the blood flow sensor is a photoacousticdoppler sensor.
 20. The mechanical chest compression device as recitedin claim 13, wherein the chest compressor further comprises a z-axisrail.